Question: Add. $\begin{aligned} 44& \\ 23&\\ 11&\\ \underline{+~6}& \\ \end{aligned}$
Explanation: First, let's add $44 + 23$. $$ $$ $$ $$ $$ ${+}$ $$ $$ $$ ${=}$ $$ $$ $$ $$ $$ $$ $$ $$ $44} + {23} = 67$ Now, let's add $11$ to $67$. $$ $$ $$ $$ $$ $$ $$ $$ ${+}$ $$ $$ ${=}$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $67 + {11} = 78$ Last, let's add $6$ to $78$. $$ $$ $$ $$ $$ $$ $$ $$ $$ ${+}$ $$ $$ ${=}$ $$ $$ $$ $$ $$ $$ $$ $$ $$ $78 + {6} = 84$ $\begin{aligned} 44& \\ 23&\\ 11&\\ \underline{+~6}& \\ 84& \end{aligned}$